1. Field of the Invention
The invention relates to relates generally to devices and methods for subterranean termite detection and control.
2. Description of Related Art
There are a variety of systems for detection and control termites known in the art, including those that incorporate housings which are implanted into the ground, and contained either an edible matrix or toxicant bait. U.S. Pat. No. 5,329,726 to Thorne et al. teaches a below ground housing for termite detection and control.
Thorne further teaches a housing which has a cartridge inserted into the housing, and the cartridge may contain either a chemical attractant to determine if termites are present or poisoned bait to kill the termites. However, to inspect the housing of Thorne to see if termites are present, one has to remove the cartridge to visually inspect it. This physically disturbs termite activity such that the termites may abandon the area and later insertion of poison could be ineffective. Further, Thorne shows a two-step method wherein the housing initially contains a non-toxic bait. If termites inhabit the housing, it is removed, and as a second step, toxic bait is inserted into the housing as a second cartridge.
U.S. Pat. No. 5,609,879 to Myles teaches a method, apparatus, and composition of treating social insects, including termites, with a poison and then releasing them. Myles discloses a trap for termites comprised of a PVC pipe and cardboard rolled within the pipe. The cardboard can also have a block of wood rolled within its center as a reserve food supply for termites. Myles also discloses an apparatus that uses heat as an attractant and then a repellent.
U.S. Pat. No. 5,921,018 to Hirose et al. teaches a device and method for luring termites which comprises an open-topped container containing wood which termites attack. Drainpipe(s) are connected to the bottom of the container, and are formed with holes through which termites can pass. Also disclosed is a method for capturing and killing termites using the termite luring device.
The ability of termites to recognize temperature anomalies is known in the art. xe2x80x9cLocation Of Food Sources By Subterranean Termitesxe2x80x9d, Ettershank, Ettershank and Whitford, J. Env. Entomol. 9:645-648 (1980), surmises an ability of subterranean termite to recognize dung pat, a preferred food source, through a temperature anomaly created by the shadow cast by the dung pat. The article supports a finding that food sources above the ground are more likely to be targeted by foraging termites, rather than subterranean food sources. Further, the article does not teach what temperature anomaly attracts the termites, as it only speculates that the cooler shadow of the dung pat on the underlying soil is the anomaly detected by termites.
The temperature anomaly that attracts the termites was however researched by the inventors herein culminating in the design and method of use disclosed in U.S. Pat. No. 5,899,018 to the inventors herein and which is herein incorporated by reference.
Most termite bait stations available commercially also are relative small in size, that is around 4-9 inches in length and about 1 inch to 2xc2xe inch in diameter. These devices require numerous change-outs before the colony is theoretically or thought to be eliminated. After further experimentation and research by the inventors herein, the inventors herein found that even larger devices installed on top of the ground surface benefit greatly from the temperature anomaly created by exposing the upper end of the device to the sunlight. Devices ranging in size from about 4 inches in cross-section to 2-4 feet in cross-section, or even larger are recommended to effectively eliminate the colony. Such devices can capture almost whole colonies, without the need to disturb the colony when several change-outs are required.
None of the devices in the above references, save the inventor""s prior patent mentioned above, address the changing philosophy of how termites behave and apply that behavior to the temperature anomaly disclosed herein and in the above mentioned patent by the inventor herein.
The present invention is a device for the control of termites comprising an elongate housing with an inside surface, an outside surface, a lower end, and a closed upper end. The lower end of the elongate housing has an opening for access to an interior of the elongate housing.
The interior of the elongate housing houses a moisture absorbing attractant wherein when the device is placed in a desired location on a ground surface with the lower end of the elongate housing facing, that is resting on, said ground surface, a temperature anomaly detectable by termites is created when at least a portion of the elongate housing is exposed to a natural radiation of the sun so as to heat the moisture absorbing attractant and cause the moisture absorbing attractant to absorb moisture from the ground surface during the day, and as the moisture absorbing attractant cools at night, the moisture absorbing attractant releases the moisture into the ground surface.
More specifically, the thin fluting technology of cardboard, which is the preferred moisture absorbing attractant, affords the highest efficiency heat exchange in the smallest package. The housing shape improves thermal transfer of aquatic properties without the application of additional external moisture enhancement structure. The main problem with regards to the manufacturing of an enhanced thermal surfaced area inside the housing is compatibility to termites with a commercially acceptable price. The thermal dynamics of the invention begin with the formation of unique helical wave forms of the cardboard""s convexity. The method of partially implanting increases the surface area over a shorter lineal length. This combination exposed to the thermal radiation of the sun dramatically induces a turbulence and culminates in an enormous increase in overall thermal transfer properties. This invention exhibits superior characteristics in air to air, water to gas, gas to water and finally on the exterior water back to gas.
The transferred state of a water solution to a gaseous state: The concept of the gaseous state offers a simple explanation of properties of water such as diffusion and saturation. As a number of molecules of water in an airborne state increases their freedom to move in all directions, a number of them return or condense to a liquid water phase which correspondingly would be greater in the evening as cooling takes place. Finally a water saturated condition achieves equilibrium. This is achieved when the rates at which the molecules go into and out of solution are equal, only then is the state of balance or equilibrium established. The inventive product achieves this characteristic.
Osmotic Pressure:
The diffusion of water into a gas is resisted by placing fluted permeable cardboard partitions between the liquid and gas volumes. The general nature of this phenomenon may be observed by implanting a so-called permeable membrane, in this case, fluted cardboard and then immerse it in water. The housing of the present invention offers a restriction to the free circulation of water allowing it only to exit from the bottom. The greater passage of water is from the diluted state into the more concentrated solution. When the hydro static pressure becomes significantly great because of the entrance of the new water through the cardboard membrane, the two opposing tendencies are balanced and the passage into or out of the cell temporarily ceases. The hydrostatic pressure is then equal to the osmotic pressure. This fact allows the present invention to remain super saturated while continuing to lose moisture exiting the bottom that is heavily cooler and more condensed then the above being held in place by osmotic pressure. These resources are replaced each and every day from shallow aquifer reserves that are unique to each geographical location. This effect demonstrates the present invention has a superior ability to achieve equilibrium using osmotic pressure against hydro static pressure.
The device further comprises means for anchoring the device to the ground surface, typically an outwardly extending flange along at least a portion of the perimeter of said lower end. The device preferably has a plurality of holes generally evenly spaced apart about a perimeter of the outwardly extending flange for anchoring the device to the ground surface. Although one hole may suffice, at least two and preferably four holes should be provided.
A device using just the moisture absorbing attractant is ideal for monitoring or detecting activity; however, once activity is detected, material should be added to eliminate the colony or a new device already containing material to eliminate the colony should be substituted or placed nearby. Such material may include one of a food source bait, a poison bait, a termitic parasite, a slow acting toxicant and any combination thereof.
Retention means over the opening at the lower end of the elongate housing is recommended for retaining the moisture absorbing attractant within the interior of the elongate housing and for deterring and minimizing human contact to the interior of the elongate housing and the moisture absorbing attractant. This retention means may be a mesh laminate, which preferably has uniform holes ranging in size from xe2x85x9 to xc2xd inch. Certainly any size mesh would work as long as it serves to retain the moisture absorbing attractant, while still allowing for the ingress and egress of termites from and to the ground to and from the interior of the elongate housing, and still minimizing human contact to the interior of the elongate housing and moisture absorbing attractant.
The mesh laminate may have a perimeter flange portion corresponding to the outwardly extending flange of the elongate housing, wherein the perimeter flange portion has generally evenly spaced apart holes about the perimeter flange, the holes corresponding to the plurality of holes in the outwardly extending flange of the elongate housing.
Means for attachment of the retention means to the elongate housing is suggested. This can be done in a number of ways known in the art, including, snap type connections, friction slip joint connections, tie-wraps through the holes, rivets, etc.
The device may have a typical top-hat type shape or be shaped in a variety of configurations to suit the landscape or obstacles on the ground. For example, the elongate housing may be a circular shape, a semi-circular shape, a polygonal shape, and a combination shape thereof.
Alternatively, the interior portion only may have its surface shaped in a circular shape, a semi-circular shape, a polygonal shape, and a combination shape thereof, with the outside surface of the elongate housing being shaped in any desired shape, including a figurine shape and/or a structure shape.
The elongate housing may be made from transparent material, semi-transparent material, opaque or solid color material, material and/or any combination of such materials. Typically, the material is plastic or polymeric, but may be metallic. Some amount of transparency is preferred to facilitate visual detection and monitoring without the need to disturb the device.
The preferred moisture absorbing attractant is rolled cardboard; although many other materials may be used including wood, combination of wood and cardboard, cow dung pat and other materials as discussed in the present inventors"" prior patent disclosed above.
As mentioned to facilitate detection or to facilitate adding a bait to an existing device containing the moisture absorbing attractant only, the closed upper end may include a cover over an open upper end, which is one of detachably engaged and sealingly engaged.
A recessed portion in a ground surface facing side of the moisture absorbing attractant may be included for possible use with other termite control devices. In such a case, the recessed portion is sized to receive a second moisture absorbing attractant, the second moisture absorbing attractant extending from inside the recessed portion a predetermined length beyond the lower end of the elongate housing. In a preferred embodiment, the moisture absorbing attractant in the elongate housing and the second moisture absorbing attractant is rolled cardboard.
Optionally added or already included in the device is one of a food source bait, a poison bait, a termitic parasite, a slow acting toxicant and any combination thereof.
The recessed portion may also be sized to receive a portion of another termite control device for which a remaining portion of the another termite control device is at least partially insertable into the ground.
The other termite control device preferably comprises a longitudinal generally cylindrical-shaped or otherwise elongate housing having an interior, and an upper and lower end; the upper end of the housing including an opening to the interior; the lower end of the housing having at least one opening to the interior for access by termites; and a moisture-absorbing attractant within the interior. The upper end of the generally cylindrical-shaped or elongate housing may have a closed upper end which is typically a cover over the opening to the interior of the generally cylindrical-shaped or elongate housing. This cover is typically detachably engaged or sealingly engaged. This other device may also include one of a food source bait, a poison bait, a termitic parasite, a slow acting toxicant and any combination thereof.
A preferred other device to use in conjunction with the present invention is a device that, when used independently, incorporates the temperature anomaly principle and thermodynamic principles described above. This device is described in the inventors"" U.S. Pat. No. 5,899,018 incorporated herein by reference. That is, when the other termite control device is inserted into the ground surface in a desired location without the use of the present invention, the temperature anomaly detectable by termites is created when the upper end of the other termite control device is exposed to the natural radiation of the sun so as to heat the moisture absorbing attractant in said other termite control device and cause the moisture absorbing attractant in said other elongate housing to absorb moisture from the ground surface during the day, and as the moisture absorbing attractant in said generally cylindrical-shaped or elongate housing cools at night, the moisture absorbing attractant in said other elongate housing releases the moisture into the ground surface.
When termite activity is detected in the other termite control device, the present invention is placed on top of the other device such that an upper portion of the other device extending above the ground surface level projects into the recessed portion of the moisture absorbing attractant of the present invention. Of course, the present invention can instead be placed in the proximity of the other device or the other device may be removed and the present invention may be placed over the area where the other device was installed.
Accordingly, the primary object of the present invention is to provide a device and method for termite detection and control which uses thermal radiation of the sun to heat a moisture absorbing attractant such that it absorbs moisture from the soil during the day and releases moisture into the soil at night to create a temperature anomaly that termites can easily detect and the termites will therefore be drawn into the device.
It is a further object of this present invention to provide a device and a method for termite detection and control where the device can be visually inspected to determine if termites are present, and a poison bait may be added without disruption of the termites. It is also a further object of this present invention to provide the device with a greater device capacity in size and shape thereby greatly enhancing the performance of the device in capturing and eliminating termites. This size and shape enhancement being enabled by the temperature anomaly characteristic described above.